March 2009, IMPORTANT UPDATE: I finally tried making mozzarella using the store-bought "milk" available here in the USA. It is pasteurized and homogenized. I used three gallons and added 1/2 tsp of liquid rennet. About 1/4 cup of buttermilk for the starter. The first thing that I noticed as being different than when I make this with non-processed milk is that while the milk set quickly, when I cut it, the curds disintegrated into tiny curds rather than remaining in the chunks for some time. It was quite difficult to strain the whey to make ricotta. (I got about a pound of ricotta). Then after letting it sit over night, it wouldn't melt although it was quite cultured by the buttermilk. I didn't add the hot water, but just added salt and it made a tasty, fairly tart cheese, something like a cross between feta and cream cheese. But it wasn't mozzarella.
I am cow-sitting for the winter so I learned how to make mozzarella because I had so much milk.
If you want a recipe, I suggest you visit Dr. Frankhauser's Cheese Page: http://biology.clc.uc.edu/fankhauser/... Dr. Frankhauser has also posted suppliers for ingredients and equipment. Good luck and have fun!
12-07: This year the museum's cow, Rain presented us with a beautiful calf, Dhana, who we are keeping. Rain is a Jersey and Dhana's Dad is a mostly white Holstein, but somehow Dhana came out almost totally black. She has some white patches on her tummy and (future) udder.
12-08 update. We have Rain back for the Winter again and I'm back to making mozzarella. Through trial and error, I've become quite good at making the mozzarella by-product: ricotta. Use the whey right after you've heated the curd (before letting it sit overnight). Heat it to 200º F and remove from heat. Then add lemon juice one TBS at a time and barely stir in the lemon juice as you watch curds form on the top. Go really slowly. When the whey looks like urine (sorry), rather than slightly cloudy, you are done adding lemon juice. Let the curd/whey set for about 15 minutes and then strain through a double layer of cheese cloth. I get about 2 lbs of ricotta from a four gallon batch of mozzarella. To think I used to give this whey to the dogs! Now they get the clearer stuff.
The music on this video is Europa by Guitar Romantica available on itunes or at: http://www.cdbaby.com/Artist/GuitarRo... The artist kindly gave me permission to use it. These guitarists are great entertainers. Check out their videos by searching youtube for "guitar romantica".